Study of Intravenous GMI-1070 in Adults With Sickle Cell Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Intravenous GMI-1070 in Adults With Sickle Cell Disease (NCT00911495), a na phase 1, phase 2 study. The primary outcome is Safety as Measured by the Number of Participants With Adverse Events.

2. Clinical Question

This is a safety-focused early-phase study, not a randomized comparison of GMI-1070 with another treatment or with no treatment. Its central question is descriptive: what adverse events were recorded among the participants who received the study drug during the stated safety period? The registry lists a primary measure based on the number of participants with adverse events, but does not post a result for that endpoint.

The record also lists pharmacokinetic outcomes, including plasma clearance and compartment volumes, and describes microvascular effects as an area of interest. The posted information does not report numerical results for those measures. Consequently, the clinical question can be framed from the study objectives, but the available record does not provide a complete set of findings with which to assess each objective.

3. Trial Design

The registry classifies this as a Phase 1/Phase 2, single-group study of intravenous GMI-1070 in adults with sickle cell disease. The study description specifies adults with stable disease in an outpatient setting. The reported enrollment is 15 participants. The sponsor is GlycoMimetics Incorporated. The record gives a start date of 2009-05, a primary completion date of 2010-07, and a status of completed.

There is no randomized allocation or masking: allocation is listed as NA and masking as none. With only a single group and no control arm, the study can describe outcomes among participants receiving GMI-1070, but it cannot make a like-for-like comparison with a separate group. The registry record does not report a comparator, and the available record does not describe specific dose levels or the details of dose titration.

The primary outcome is the number of participants with adverse events, with a timeframe of 28 days. The stated safety population is all enrolled subjects. The record also names secondary pharmacokinetic outcomes: total plasma clearance, volume of the central compartment, intercompartmental clearance, and volume of the peripheral compartment. The study summary additionally identifies microvascular effects as an assessment area, but numerical results for those outcomes are not reported in the registry record.

The registry lists six outcome measures, while the available information names the primary safety measure and four secondary pharmacokinetic measures. The remaining outcome details are not reported in the registry record. No analysis entries are listed. This means the record supplies some design and outcome definitions, along with limited adverse-event counts, but does not give a complete account of outcome analyses or results.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: All enrolled subjects were analyzed for safety.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Safety as Measured by the Number of Participants With Adverse Events, measured over 28 days.

The primary endpoint is safety measured as the number of participants with adverse events over 28 days. It is a participant-count outcome: it concerns how many people experienced an adverse event, rather than the total number of separate events. The registry specifies that all enrolled subjects were analyzed for safety.

A participant-based safety endpoint is useful for describing how many people in the study were affected during the stated observation period. It can provide a straightforward summary of recorded safety experience in the enrolled group. It does not, by itself, establish whether an event was caused by the study drug, how severe or long-lasting it was, or how the experience compares with another treatment. Those interpretations require details and comparisons that are not included in the primary endpoint definition.

The posted adverse-event information distinguishes serious adverse events from other adverse events. It reports zero participants with serious adverse events and nine participants with other adverse events, each among 15 at risk. However, the primary outcome result itself is not reported in the registry record as a single outcome analysis. The adverse-event counts should therefore be read as the specific posted categories, not as a substitute for unreported endpoint details. The record does not provide event descriptions, timing, or a complete account of severity beyond the serious-versus-other distinction.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design allow?

In a single-group study, outcomes are described among participants who receive the intervention. General statistical interpretation: a comparison group helps distinguish an intervention-related difference from changes that could occur over time, background event rates, or other influences. Without that group, the observed counts remain descriptions of this study’s participants. Here, allocation is listed as NA, masking as none, and the model as single-group. The record does not describe a like-for-like control comparison.

How should participant counts be read?

The primary endpoint is expressed as the number of participants with adverse events, and the posted adverse-event categories give participant counts alongside the number at risk. The serious-event category lists zero affected among 15 at risk; the other-event category lists nine affected among 15 at risk. These are counts, not measures of the total number of event episodes. A participant may experience more than one event, but event-level counts and descriptions are not reported in the registry record.

General statistical explanation: counts are most informative when their population, event definition, and observation period are clear. The primary outcome specifies a 28-day timeframe and a safety population of all enrolled subjects. The adverse-event listing gives the group and numbers at risk, but does not supply detailed definitions or event narratives. The primary endpoint’s analyzed result is not separately reported in the registry record, so the category counts should not be mistaken for a complete endpoint report.

What would an estimate and confidence interval add?

General statistical explanation: an estimate summarizes the observed data, while a confidence interval conveys the uncertainty around that estimate under the assumptions of the analysis. A narrow interval would indicate greater precision than a wide interval, though precision does not establish causation or clinical importance. The registry record does not report confidence intervals or an analysis estimate for the primary safety endpoint. It is therefore not possible to judge the precision of an endpoint estimate from the posted analysis information.

Are hypothesis tests reported?

The record lists no analysis entries. It does not report a p-value, a formal hypothesis test, or an adjusted comparison for the primary endpoint. General statistical explanation: a hypothesis test evaluates data against a specified statistical model and question; a p-value is not a measure of the size or importance of an effect. In this single-group study, a test against a comparator would also require a defined comparison that is not present in the record. No unreported test or analysis plan should be inferred.

How do the sample-size illustrations relate to the study?

The stated planning assumptions use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They describe planning illustrations based on a fraction of an observed effect. For non-time-to-event outcomes, the stated convention is participants per arm for 80% or 90% power; time-to-event illustrations use a total number of events. These are planning concepts, not observed characteristics of this study. The study itself is single-group, and the registry record does not report its own sample-size justification. The illustrations should not be interpreted as observed power or as evidence that a comparative trial was conducted.

Why can over-dispersion matter?

General statistical explanation: over-dispersion occurs when observed variability is greater than a model assumes. If it is ignored, uncertainty can be understated and statistical conclusions can appear more precise than warranted. It is relevant to some count-data analyses, but the primary outcome is defined as participants with an event, and the registry record does not describe an over-dispersion model or any other analysis model. No conclusion about the use or suitability of such a model can be drawn from the record.

What analysis details are unavailable?

The registry record does not report the statistical plan, the handling of missing outcome data, interim analyses, or a multiplicity adjustment. It states that all enrolled subjects were analyzed for safety, but does not report analysis populations for other outcomes. It names four secondary pharmacokinetic outcomes, while numerical results and analysis details for those outcomes are not reported in the registry record. The record also identifies microvascular effects in the study description without providing corresponding result details. These omissions limit assessment of precision, completeness, and the relationship between planned outcomes and reported findings.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("GMI-1070")
n      <- c(15)
events <- c(9)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  GMI-1070  15  9  60.0  32.3  83.7  35.7  80.2  35.4  80.2

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists six outcome measures. It identifies the primary safety measure and four named secondary pharmacokinetic outcomes: total plasma clearance, volume of the central compartment, intercompartmental clearance, and volume of the peripheral compartment. The available information does not identify all six measures or give results for the pharmacokinetic outcomes. Although the study summary mentions microvascular effects, corresponding outcome definitions and results are not reported in the registry record.

When a study evaluates multiple outcomes or performs multiple statistical tests, the chance of at least one apparently notable result can increase. General statistical explanation: multiplicity procedures can address that issue by changing how evidence is evaluated across a family of tests. The registry record does not report whether a multiplicity adjustment was planned or used. It also does not report an analysis plan or analysis entries, so the intended hierarchy among outcomes and tests cannot be determined.

The safety population is stated as all enrolled subjects. The record does not report how missing outcome observations were handled, whether any data were missing, or the analysis populations for outcomes other than safety. Deaths are not reported in the registry record. The absence of these details does not establish that data were missing or that a particular method was used; it means completeness and handling cannot be assessed from the record.

No interim analyses are reported in the registry record. That absence should not be interpreted as confirmation of the study’s interim-monitoring practices. In general, analysis timing and rules can affect interpretation when repeated assessments are made, but the record does not provide enough information to determine whether that issue arose in this study.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The posted adverse-event figures distinguish serious events from other events. For the GMI-1070 group, zero participants with serious adverse events are listed among 15 at risk. The other adverse-event category lists nine participants affected among 15 at risk. These are participant counts within the study group, not a comparison against an untreated or active-control group.

A zero serious-event count means that no participants were recorded in that category in the posted figures. General statistical explanation: observing zero events does not establish that the underlying risk is zero; a finite study group can fail to capture events that may occur in a broader population. The count also does not determine whether the study was large enough to characterize uncommon events.

The nine participants in the other-event category show that events outside the serious category were recorded. The registry record does not provide the event terms, descriptions, timing, or severity details for those participants. It also does not report deaths. The record’s primary endpoint is the number of participants with adverse events over 28 days, but a separate analyzed result for that endpoint is not reported. The category figures therefore support a limited descriptive reading, not a complete assessment of safety or a conclusion about causation.

13. What the Result Does, and Does Not, Mean

The record documents a Phase 1/Phase 2, single-group study of intravenous GMI-1070 in adults with stable sickle cell disease. It reports enrollment of 15 participants and specifies that all enrolled subjects were analyzed for safety. The posted adverse-event information records zero participants with serious adverse events and nine with other adverse events, each among 15 at risk. These figures describe the study group and the categories recorded in the registry.

They do not show whether GMI-1070 caused or prevented an event. Without a comparator group, the study cannot separate the experience during treatment from the background course of disease or other influences. The serious-event count also does not establish that serious events cannot occur, and the other-event count cannot be fully interpreted without event descriptions and details. The record does not report deaths.

The study objectives include safety, pharmacokinetics, and microvascular effects. The registry record does not report numerical pharmacokinetic or microvascular findings. It also does not provide an analysis entry or a separately reported primary endpoint result for the number of participants with adverse events over 28 days. The posted counts should not be treated as a complete account of all study outcomes.

In statistical terms, the available results are descriptive and limited in precision because no estimate or confidence interval is reported for the primary endpoint. No comparative treatment effect can be estimated from the design described. The record supports statements about what adverse-event counts were posted, but not about relative safety, effectiveness, or effects on sickle cell disease. Those questions require information beyond the reported single-group counts.

14. Why This Trial Matters Statistically

This study illustrates why design and outcome reporting matter when interpreting early-phase clinical research. The record identifies a Phase 1/Phase 2 study of intravenous GMI-1070 and describes safety, pharmacokinetics, and microvascular effects as areas of assessment. Its single-group structure means the posted findings describe participants who received the study drug rather than a randomized contrast with another group.

The adverse-event counts show how to separate a zero count for serious events from a nonzero count for other events. Keeping the categories distinct prevents the serious-event figure from being mistaken for an absence of all adverse events. At the same time, counts without event descriptions, uncertainty estimates, or a comparator offer only a limited statistical picture. They cannot establish causation or provide a comparative safety estimate.

The record also demonstrates the difference between an outcome definition and a reported result. It specifies a 28-day primary safety endpoint and a safety population, but does not provide a separate analyzed result for that endpoint. The named pharmacokinetic outcomes and the study’s stated interest in microvascular effects likewise do not come with numerical results in the registry record. Clear reporting of outcomes, analyses, and uncertainty is necessary for readers to assess what the data support.

Finally, planning assumptions should not be confused with the design actually used. Sample-size illustrations based on a two-arm allocation do not convert a single-group study into a comparative trial, and they are not observed power. Reading design, endpoint, and result information together helps keep statistical conclusions within the limits of the evidence documented in the record.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for interpretation is the absence of a comparison group. The trial is listed as single-group, with allocation marked NA and no masking. The adverse-event counts therefore cannot be interpreted as differences relative to another treatment or to no treatment. They also cannot isolate the effect of GMI-1070 from other factors.

The registry record reports enrollment of 15 participants, but does not provide a separate primary endpoint analysis or an uncertainty estimate. It lists zero participants with serious adverse events and nine with other adverse events, while omitting event descriptions and details about timing or duration. Deaths are not reported in the registry record. These limits prevent a fuller assessment of the nature and precision of the safety findings.

The record identifies safety, pharmacokinetics, and microvascular effects as study aims, but numerical results are not reported for pharmacokinetic or microvascular outcomes. Although six outcome measures are listed, the available information does not identify all of them. No analysis entries are listed, and the statistical plan, missing-data methods, interim analyses, multiplicity approach, and sample-size justification are not reported in the registry record.

The study description refers to titrating doses, but specific dose levels and dosing procedures are not reported. The information available also does not describe participant flow, exclusions, or completeness of outcome data beyond stating that all enrolled subjects were analyzed for safety. These reporting limits do not show that a particular method or event was absent; they constrain what can be concluded from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study of Intravenous GMI-1070 in Adults With Sickle Cell Disease — NCT00911495.
• Registry record last updated 2020-05-11; status last verified 2020-05.
• Results first posted 2013-05-03.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed Phase 1/Phase 2, single-group study of intravenous GMI-1070 in adults with stable sickle cell disease. Enrollment was 15. The record gives a start date of 2009-05 and a primary completion date of 2010-07. Allocation is listed as NA and masking as none.

The primary endpoint is the number of participants with adverse events over 28 days; all enrolled subjects were analyzed for safety. Posted adverse-event counts list zero participants with serious adverse events and nine with other adverse events among 15 at risk. The registry record does not report a separate primary endpoint analysis, deaths, numerical pharmacokinetic or microvascular results, or analysis entries. The study has no control group, so its posted counts are descriptive rather than comparative.